1. Field of the Invention
The present invention relates to a sensor-equipped wheel support bearing assembly having a load sensor incorporated thereon for detecting a load imposed on a bearing unit employed in an automotive vehicle.
2. Description of the Related Art
As a technique for detecting a load imposed on each of vehicle wheels of an automotive vehicle, a sensor-equipped wheel support bearing assembly has been suggested, in which a sensor unit, made up of a strain generating member and a strain sensor fitted to this strain generating member, is fitted to a stationary ring of the bearing unit and in which the strain generating member has a contact fixing segments, provided at least two locations, relative to the stationary ring and also has a cutout portion, at least one location, between the neighboring contact fixing segments, with the strain sensor arranged in this cutout portion. (See, for example, the Patent Document 1 listed below.)
According to this sensor-equipped wheel support bearing assembly, when a load is imposed on a rotating ring incident to travel of the automotive vehicle, the rotating ring deforms through rolling elements and such deformation in turn brings about a strain in the sensor unit. The strain sensor provided in the sensor unit detects a strain induced in the sensor unit. If the relation between the strain and the load is determined by means of a series of experiments and/or simulations in advance, the load acting on a vehicle wheel can be detected from an output of the strain sensor.
Other than the above, as a related technique, a sensor-equipped wheel support bearing assembly has also been suggested, in which the load is detected by detecting a strain occurring in a flange outer diametric face of an outer ring of the wheel support bearing assembly that serves as a stationary ring. (See, for example, the Patent Document 2 listed below.). In addition, a wheel support bearing assembly including a strain gauge provided on an outer ring of the wheel support bearing assembly for the detection of a strain has been suggested. (See, for example, the Patent Document 3 listed below.)
[Patent Document 1] JP Laid-open Patent Publication No. 2007-057299
[Patent Document 2] JP Laid-open Patent Publication No. 2002-098138
[Patent Document 3] JP Laid-open Patent Publication No. 2003-530565